Free online tools that run in your browser
PDF and image tools, calculators, countdowns and 2027 planners — free and without sign-up. Most tools work entirely on your device, and the PDF and image tools never upload your files. See all tools by category.
Get a file ready to submit
- Image Compressor (to 200KB, 100KB, 50KB)Compress JPG, PNG or WebP photos to a target file size such as 200KB or 100KB and see the exact size before you download.
- Image Resizer (exact pixels, batch)Resize images to exact pixel dimensions without uploading — batch, no cropping or center crop, JPG/PNG/WebP.
- Merge PDF (combine PDF files)Combine several PDFs into one file in the order you want — without uploading them anywhere.
- Compress PDF (reduce file size)Shrink PDFs by recompressing the photos and scans inside, while keeping text searchable.
Count days and plan dates
- Days Until Calculator (countdown)Count down the days until a birthday, holiday, exam or trip — or the days since a past date.
- Date Calculator (days between dates)Count the days between two dates, or add and subtract days from a date — with weeks and months.
- Age Calculator (by date of birth)Calculate exact age in years, months and days from a date of birth, plus days until the next birthday.
- Time Zone ConverterConvert a time between any two cities and see the same moment in 30 major cities, with daylight saving time applied.
Plan 2027 at work
- 2027 Federal Holidays & Printable CalendarAll 2027 US federal holidays with actual and observed dates, plus a black-and-white Letter calendar you can print.
- 2027 Biweekly Pay CalendarEnter one real payday to see every 2027 payday, months with 3 paychecks, and a second person’s schedule side by side.
- 2027 PTO PlannerCompare how many days in a row you get off around each 2027 holiday with 1, 2 or 3 PTO days, using your own holidays and work days.
Convert and calculate
- Speed Converter (mph to km/h)Convert miles per hour to kilometers per hour, knots, meters per second and feet per second, with speed-limit charts.
- Length Converter (cm to inches, feet)Convert inches, feet, yards and miles to centimeters, meters and kilometers — with a height chart in feet and inches.
- Percentage Calculator (percent off, % change)Find X% of a number, what percent one number is of another, percentage increase or decrease, and sale prices.
- Final Grade CalculatorWhat do I need on my final? Enter your current grade, target and final exam weight.
Korea Essentials
We are based in South Korea, so these are Korea questions we can explain with confidence.
- Korean Age Calculator (vs international age)Compare international age, traditional Korean age and year age for any birth date, and see when each one changes.
- KST Converter (Korea time to your time)Convert a time in Korea (KST) to your local time, EST/EDT, PST and other cities, with the date change shown.
Who runs this site
phoneline.kr is run by a one-person team in South Korea. Our main service helps people in Korea keep track of several mobile phone lines — plan conditions, plan-change dates and promised benefits — with reminders before a deadline.
Available in English: the free tools on this site. Korean only: the phone-line manager (Android app and web dashboard), alerts, deal listings, guides and the community. You can use them with a browser translator, but their screens and support are in Korean.
Privacy: the tools do not ask you to sign in. Visits and tool use are counted with a random visitor ID that is not linked to your name or email, and the files and text you enter are never collected. Details are in our privacy policy (Korean). Contact: phonetech.alert@gmail.com